Integrated fiber optic cable fan-out connector

ABSTRACT

An integral fan-out connector assembly for fiber optic cables includes a connector housing that provides an integrated fan-out housing and connection adapter. The fan-out connector housing may be configured with a variety of cable adapters, and may be installed as a ‘plug and play’ type solution where it will be ready to accept a feed cable for use when needed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/170,265 filed Jan. 31, 2014, and a divisional of U.S. patentapplication Ser. No. 15/392,285 file on Dec. 28, 2016, which areincorporated herein by reference in its entirety.

BACKGROUND

The use of fiber optics for communications purposes continues to grow.Data, voice, and other communication networks are increasingly usingfiber optics to carry information. Conventional fiber optic cablesinclude optical fibers that conduct light in the transmission of voice,video, and data information. Optical cables have the advantages of largebandwidth and low power loss. Typical applications for optical cablesinclude fiber-to-the-curb (FTTC), fiber-to-the-home (FTTH),fiber-to-the-desk (FTTD), fiber-to-the-antenna (FTTA), plenum, riser,local area networks (LANs), and closed circuit television systems(CCTV).

In a fiber optic network, each individual fiber is generally connectedto both a source and a destination device. Additionally, along the fiberoptic run between the source and the destination, various connections orcouplings may be made on the optical fiber to adjust the length of thefiber. Each connection or coupling requires a connector and adapter toalign the fibers such that the light can transmit over the connectionwithout interruption.

Fiber optic connectors of a wide variety of designs have been employedto terminate optical fiber cables and to facilitate connection of thecables to other cables or other optical fiber transmission devices. Atypical fiber optic connector includes a ferrule which mounts andcenters an optical fiber or fibers within the connector. The ferrule maybe fabricated of such material as ceramics. A multi-fiber optic cable isterminated in the connector, and a plurality of individual opticalfibers of the cable may be terminated in the ferrule. A popular type offiber optic cable is a multi-fiber flat, or ribbon cable. Since theindividual optical fibers of the cable are very closely spaced, afan-out connector may often be used for receiving and spreading theindividual fibers of the cable so that the fibers are more easilyconnectorized for individual use. The individual fibers may extend awayfrom the fan-out within a plurality of manipulatable tubes that alsoprotect the fibers.

Fan-out blocks or modules are generally mounted within an enclosure, arewall mounted or bracket mounted, and include a direct feeder cable inputthat feeds into the housing and provides the individual fibers of thefan-out. The end of the feeder cable may include a fiber optic cableconnector for connection to a cable feed, such as a feed in a basestation at a distance from the enclosure. A fan-out kit may includeterminal fiber connectors, a main feed connector, a fan-out block, andintegral fiber optic cables that extend from the feed connector on theone end, to and through the fan-out block and to the individual terminalconnectors on the other end. There remains a need for a simplifiedfan-out system that may be adaptable to a variety of uses.

SUMMARY

An integral fan-out, connector unit allows for the elimination of one ofthe housing components, as well as, if desired, elimination of a feedcable directly into the housing. The fan-out connector may be configuredwith a variety of cable adapters, and may be pre-installed for use as a‘plug and play’ type solution, where it will be ready for use whenneeded. Then, at the time when needed, a main feeder cable may beplugged in directly for use. While the fan-out connector housing may beconfigured for a plug-in feeder cable, the same housing may also beadapted for use with a regular cable gland that allows for direct cableinput.

In an embodiment , a fan-out housing for fanning out optical fibers of amulti-fiber source includes a main body defining an interior cavitytherein and having a first body portion and a second body portion spacedfrom the first body portion. The fan-out housing also includes a fan-outmember releasably attachable with the first body portion for fanning outoptical fibers, and a cable receptacle releasably attachable with thesecond body portion. The cable receptacle may be either of an opticalfiber adapter configured for attachably receiving a connector of amulti-fiber optical cable, or an optical fiber cable gland configuredfor passage of a multi-fiber optical cable therethrough.

In an embodiment, a fan-out assembly for connecting fiber optic cablesof a multi-fiber optical cable to a plurality of fiber optic terminalsincludes a housing defining an interior cavity therein, a plurality ofpigtail cable segments having a first end disposed within the housingand a free end disposed away from the housing, at least one opticalfiber extending through each pigtail cable segment, with each opticalfiber including a first end disposed within the interior cavity and asecond end disposed at the free end of the pigtail cable segment, afirst optical fiber connector collectively terminating the first ends ofa plurality of the optical fibers, and at least one second optical fiberconnector mounted to the free end of each pigtail cable segment andterminating the second end of the at least one optical fiber of thepigtail cable segment, the second optical fiber connectors beingconfigured to mate with the fiber optic terminals. The housing alsoincludes an optical fiber adapter having a first end open to theinterior cavity for receiving the first optical fiber connector therein,and a second end exposed externally of the interior cavity for receivinga connector of a multi-fiber optical cable to mate the optical fibers ofthe multi-fiber optical cable with the first ends of the optical fibersof the pigtail cable segments.

In an embodiment, a method is provided for connecting remote radio unitsof a cellular antenna tower with a base transceiver station via amulti-fiber optical cable that includes a terminal connector. The methodincludes attaching a fiber optic fan-out connector assembly adjacent theremote radio units, the fan-out connector assembly including a housingdefining an interior cavity, a plurality of pigtail cable segmentsextending from the housing, with each of the plurality of pigtail cablesegments having a first end disposed within the housing and a free enddisposed away from the first end, at least one optical fiber extendingthrough each pigtail cable segment and having a first end within theinterior cavity and a second end at the free end of the pigtail cablesegment, optical fiber connectors mounted to the free ends of eachpigtail cable segment and terminating the second end of the at least oneoptical fiber of the pigtail cable segment. The housing also includes amating connector for connecting first ends of the optical fibers withthe connector of the multi-fiber optical cable, wherein the matingconnector includes a plug-in socket for receiving the connector of themulti-fiber optical cable therein. The method also includes connectingthe second optical fiber connectors of the pigtail cable segments to theremote radio units, and connecting the multi-fiber optical cable fromthe fan-out connector assembly to the base transceiver station, whereinthe connecting includes plugging the connector of the multi-fiberoptical cable into the plug-in socket of the mating connector.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A and 1B depict installations of a fan-out connector according toembodiments.

FIGS. 2A and 2B depict fan-out connector assemblies according to anembodiment.

FIGS. 3A and 3B show a fan-out housing connector according to anembodiment.

FIGS. 4A-4D depict alternate views of a fan-out connector according toembodiments.

FIG. 5 provides an exploded view of a fan-out connector according to anembodiment.

FIGS. 5A -5D depict alternative components of a fan-out connectoraccording to embodiments.

FIG. 6 provides a perspective view of a drum component of a fan-outconnector according to an embodiment.

FIGS. 6A-6D provide alternative configurations for a drum component of afan-out connector according to embodiments.

FIGS. 7A-7E illustrate representative steps for assembly of furcationtubings with a drum component according to an embodiment.

FIG. 8 illustrates assembly steps of a fan-out connector according to anembodiment.

FIG. 9 provides an alternative furcation tube connection according to anembodiment.

FIG. 10 provides a cross-sectional view of an angled fan-out connectoraccording to an embodiment.

DETAILED DESCRIPTION

Installations of fiber-to-the-antenna (FTTA) fiber optic systems, suchas those that provide wireless phone and internet services, may besimplified by providing plug-and-play type connection assemblies thatconnect the remote radio units to base transceiver stations. Asrepresented in FIG. 1A, remote radio units 2 may typically be mounted onantenna towers 1, and a base transceiver station 5 may be located nearthe base of the tower, or a short distance away from the tower.Alternatively, such remote radio units 2 may be mounted on the tops oftall buildings or other tall structures, such as water towers.

As represented in FIG. 1A, but exaggerated in size, a fan-out connectorassembly 140 may be installed as a stand-alone distribution system inthe vicinity of the remote radio units 2. The assembly 140, as discussedin more detail below, and shown in greater detail in FIG. 2A, mayinclude a fan-out connector housing 134 having a plurality of fiberoptic cables, or pigtails, 108 extending therefrom. The fan-outconnector housing 134 may be fastened in place with a clamping device,such as, for example, a cable tie or hose clamp type securing device.The fiber optic cables 108 may be terminated by fiber optic connectors122 that are configured to connect with the remote radio units 2. Aninstalled fan-out connector assembly 140 may then be ready forplug-and-play use.

A main feeder cable 150 may be provided between the base station 5 andthe installed fan-out connector assembly 140. The distal end of thefeeder cable 150 may be terminated with a connector 145 that plugs intothe fan-out connector housing 134 to connect individual fiber opticcables in the feeder cable with the fiber optic cables 108. Individualfibers of the feeder cable 150 therefore do not need to beconnectorized, providing for an easier installation of the main feedercable.

In an alternative embodiment, as shown in FIG. 1B, a fan-out connectorassembly 140 (housing 134, pigtail cables 108 and connectors 122) mayalso provide plug-and-play features for a fiber optic wall mount cabinet10. Cabinet 10 may be a cabinet of, for example, but not limited to, apatch panel, an equipment rack, or a remote radio distribution terminalsuch as may be mounted on an antenna 1 in the vicinity of the remoteradio units 2. A cabinet 10 may have a side wall 22 connected at a firstend to a bottom wall 28 and at a second end to a top wall 20. A backwall 30 may be substantially perpendicular to edges of the top wall 20,the side wall 22, and the bottom wall 28 so that the side wall, bottomwall, top wall, and back wall form a substantially rectangularenclosure. The back wall 30 may include mounting features, such as keyhole mounting slots 58 configured for allowing fastening of the cabinet10 to a wall surface.

The cabinet may also have a patch panel wall 32 located within thecabinet for connecting fiber optic cable 108, 116. Such a patch panelwall 32 may extend between the top wall 20 and the bottom wall 28 andsubstantially parallel to the side wall 22. The patch panel wall 32 maydivide the interior of the cabinet 10 into an incoming chamber 34 and anoutgoing chamber 36, thereby creating two surfaces, a first incomingsurface 32 a and a second exiting surface 32 b. The cabinet 10 may havean arrangement of knock-outs or slots 38, 40, 42, 44 in the top wall 20and the bottom wall 28 for routing fiber optic cable into the incomingchamber 34 and out of exiting chamber 36. On the incoming side (chamber34), fiber optic cables 108 may extend from a fan-out connector 134, asdiscussed further below, at knock-outs 38 to the incoming surface 32 a.On the outgoing side (chamber 36) fiber optic cables 116, terminated onexiting surface 32b, may be routed out of the cabinet 10 through slot 44to active equipment, such as a server.

The cabinet 10 may also be provided with slack management spools 106that allow for spooling extra incoming cables 108 while maintaining aminimum bend radius in the cables. Further, strain relief brackets 110,111 may be provided along with any anchor ties 132 for bundling of anyfiber optical cable 108, 116 that may enter or exit each chamber. Otherarrangements of the parts of the cabinet 10, such as the cable slots andpatch panel wall are also possible.

The fiber optic wall mount cabinet 10 may also include lockable covers(not shown) to cover the incoming chamber 34 and exiting chamber 36. Afirst cover may be hingedly connected to the side wall 22 such that thefirst cover is perpendicular to the side wall 22 and substantiallycloses the incoming chamber 34. A second cover may be hingedly connectedto the back wall 30, opposite to the side wall 22 to substantially closethe outgoing chamber 36. When fully open, the second cover may enablefull access to the exiting chamber 36 from both the front and side ofthe cabinet 10. The first cover and second cover may also include keyedlocks and handles (not shown), located preferably on the outer edges ofeach cover, for providing security and accessibility, respectively, tothe respective chambers 34, 36. In an alternative embodiment, each covermay be hingeless, completely removable, and releasably secured to thecabinet 10 with snaps, clips, or the like. Other arrangements are alsopossible.

The patch panel wall 32 may include a number of removable covers 120that cover openings in the wall that provide access between the chambers34, 36. The openings in the wall may include connector adapters forreceiving connectors 122, 60.

The fiber optic connector adapter arrays may serve as termination pointsfor incoming fiber optic pigtails 108, terminated by connectors 122, andexiting fiber optic cables 116, terminated by connectors 60. To helpseparate and guide the cables, guide plates 124, 126 may also beprovided on the wall 32. The connector adapters may be configured forany type of fiber optic connectors 122, 60, such as, but not limited to,LC, FC, SC, ST, or MPO (or similar) types of fiber optic connectors. Inaddition, each of the adapters in an array may be configured to acceptthe same type of connectors, or, individual ones of the adapters in anarray may be configured to individually accept different types ofconnectors.

FIGS. 2A and 2B show isolated views of fan-out connector assemblies 140,including the fan-out connector 134 with attached cables 108 andconnectors 122. For various housings 10 and end uses, such as in an FTTAsystem as described above, assemblies 140 may be provided with differentlengths and types of cables 108, as well as different types ofconnectors 122. Assemblies 140 may be sold pre-assembled, oralternatively, the individual components (fan-out connector 134, cables108 and connectors 122) may be provided separately for assembly by anend user.

A protective/dust cap 138 may be provided for covering and protectingthe open end 134 a of the fan out connector 134. Various configurationsand features of the fan-out connector 134 are discussed further below.In an embodiment as depicted in FIGS. 2A and 2B, a feed cable 150 may beconfigured with an appropriate connector 145 for connection of the feedcable to the fan-out connector 134, and thereby connection of the fiberoptic cables within the feed cable with fiber optic cables in the cables108. With such an embodiment, a pre-assembled fan-out assembly 140 maybe installed in a housing, such as housing 10, via a knock-out in thehousing wall, as depicted in FIG. 1. In an embodiment, housings may besold with one or more pre-installed fan-out assemblies.

After installation in a housing, and when needed for use, a feed cable150 may simply be plugged into the fan-out connector 134 via he end 134a. The fan-out connector 134 therefore provides ‘plug-and-play’ ease ofuse. In a further embodiment, as also discussed below, a feed cable 150could be an integral component of a fan-out connector assembly whereinthe fiber optic cables within the feed cable are integral with the fiberoptic cables of cables 108 so that no connector 145 is needed.

The fan-out connector 134, may include a housing that, as shown ingreater detail in FIGS. 3-5, for example, may include a main housingbody 200, a fan-out member 202, and an optical fiber receptacle 204. Inan embodiment, a fan-out housing for fanning out optical fibers of amulti-fiber source may include a main body 200 defining an interiorcavity 210 therein and having a first body portion and a second bodyportion spaced from the first body portion. The fan-out housing may alsoinclude a fan-out member 202, discussed further below, releasablyattachable with the first body portion for fanning out optical fibers108, and a cable receptacle 204 releasably attachable with the secondbody portion. As discussed in more detail below, the cable receptacle204 may be either of an optical fiber adapter configured for attachablyreceiving a connector of a multi-fiber optical cable, or an opticalfiber cable gland configured for passage of a multi-fiber optical cabletherethrough.

In an embodiment as shown in FIGS. 3-5, for example, the fan-out membermay be a drum, and the receptacle may be an adapter. In an embodiment,housing body 200 may be essentially cylindrical and define a centrallongitudinal cavity 210. The housing 200 may be formed of any rigidmaterial such as metal or polymers, and may be molded or machined. In anembodiment, the housing 200 may be machined aluminum, or may beinjection molded and may be formed of a polymer, such as polybutyleneterephthalate, polycarbonate, polystyrene, or polyethylene, to provide afew non-limiting examples.

In an embodiment, a housing 200 may include reinforcing bands 201 thatmay be disposed about the exterior of the housing. The bands 201 mayprovide a gripping feature that provide for a better grasp of thehousing, for example, during installation or assembly. An end flange 201a may provide a seat against which the adapter 204 abuts as an insertionstop. An O-ring 215 may be provided between a flange 205 of the adapter204 and the end flange 201 a to provide a seal for keeping moisture outof the interior 210. The O-ring 215 may be silicone, or any other typeof elastomeric polymer, such as butyl rubber, polyisoprene rubber,butadiene rubber, or nitrile rubber, to provide a few non-limitingexamples. As an alternative to the O-ring 215, a flat elastomeric washermay be provided between the flange 205 of the adapter 204 and the endflange 201 a.

The fan-out member 202 may be disc-shaped, and may be configured as acable guide drum. A first end 200 a of the housing may be configured forreceiving the cable guide drum 202 therein. In an embodiment as shown,the drum 202 may be configured to fit within the end 200 a so that anexterior surface 202 a is flush with the end 200 a. In an alternativeembodiment, as depicted in FIG. 4D, a portion 203 a of the drum 202 maybe configured to be disposed within the end 200 a and a portion 203 bmay be configured to protrude axially from the end. The protrudingportion 203 b may have a larger diameter than the insertion portion 203a to provide an insertion stop, and the diameter of the protrudingportion may match the diameter of the housing end. As shown in FIGS. 4Cand 4D, an O-ring 212 may be disposed between the housing 200 and thedrum 202 to provide a seal for keeping moisture from entering into thecavity 210. The O-ring 212 may be may be silicone, or any other type ofelastomeric polymer, such as butyl rubber, polyisoprene rubber,butadiene rubber, or nitrile rubber, to provide a few non-limitingexamples.

The end 200 a of the housing 200 may include a key slot 220 and the drum202 may include a key 222 configured to fit within the key slot andprevent rotation of the drum within the housing. Alternatively, the drum202, may include a slot and the housing 200 may include a key memberthat it's the slot. In an embodiment, the drum 202 may be retainedwithin the end 200 a by screws 225. In one embodiment, the housing end202 a may include holes 226 for receiving the screws 225 therethrough,and the drum 202 may include threaded holes 228 for receiving thescrews. Holes 226 and 228 may be properly aligned for the screws bymeans of the keying features 220, 222. In an alternative embodiment,holes 226 may be threaded, and the screws 225 may, if desired, be atleast partially threaded into the housing 200 prior to placement of thedrum 202 into the housing. Upon insertion of the drum 202 fully into thehousing 200 the screws 225 may be tightened into place to retain thedrum in the housing. If the holes 226 are threaded, the drum may or maynot include the holes 228, wherein a tightening of the screws into thehousing end may engage the ends of the screws with the drum 202 tofrictionally retain the drum within the housing. Alternatively, asrepresented in FIG. 5A, to avoid alignment issues, and possiblyeliminate the need for keying features, the drum 202 may include anannular groove 229 disposed about the drum 202 and the screws 225, bymeans of threaded holes 226, may be tightened into the annular groove inany relative position of the drum 202 within the housing 200. The screws225 may frictionally engage the drum within the groove 229 to preventrotation of the drum within the housing.

If a permanent attachment of the drum 202 to the housing 200 is desired,an adhesive may be used to retain the drum in the housing, and anykeying alignment features and assembly holes may not be needed. Inaddition, other types of coupling may also be used, such as a snaptogether coupling wherein a projecting portion of at least one of thehousing 200 and drum 202 may be configured to snap into and be retainedwithin a groove or slot in the other of the housing or drum. Oneadditional type of coupling may include biased tabs which projectradially inwardly from the end 200 a and are configured to engage andretain the drum within the housing, wherein the tabs are movableradially outwardly to allow for passage of the drum into the housingend, and then return to an original configuration to retain the drumwithin the housing. Such tabs may be configured to be opened manually,or with a tool to allow for removal of the drum.

FIG. 6 provides a perspective view of a drum 202, such as represented inFIGS. 4C and 5. In an embodiment as shown, the surface 202 b may berecessed from an insertion end to form a cavity (discussed furtherbelow). In an embodiment, a plurality of orifices 240 may be providedthrough the drum for receiving the cables 108. As represented in FIGS.6C and 6D, a variety of different drums 302, 402 may be provided, andthe different drums may provide alternative configurations with regardto the number and size of the orifices 340, 440. As represented by FIG.6C, the size of the openings may be configured according to the size ofthe cable that is needed, or, as represented by FIG. 6D, forapplications where a greater number of cables are needed, the number ofthe openings 440 may be configured accordingly. FIG. 6D represents adrum such as may be used in the configuration as depicted in FIGS. 2Aand 2B wherein twelve cables 108 fan-out from the housing.

As represented in FIGS. 4C and 5, a second end 200 b of the housing 200may be configured for receiving an adapter 204, or alternatively, apass-through cable gland 250 therein. Various configurations/sizes ofadapters 204 and/or cable glands 250 may be provided for installation atthe second end 200 b of the housing 200. In an embodiment as shown, thesecond end 200 b may be internally threaded for threaded receipt of anadapter 204 or cable gland 250 therein. The adapter 204 or cable gland250 may have an externally threaded end 204 a, 250 a that iscorrespondingly threaded for being rotatably threaded into the housing200. Alternatively, other types of engagement couplings may be used forretaining an adapter 204 or gland 250 on the housing 200, such as thosedescribed above for retaining the drum within the end 200 a.

An adapter 204 or cable gland 250 may include a radially extendingflange 205, 251, respectively, that may act as a stop for limitinginsertion of the adapter or gland into the housing, while also providinga seat for engaging with the O-ring 215 and compressing the O-ringagainst the flange 201 a of the housing 200. In a further embodiment,instead of sealing with an O-ring, such as O-ring 215, a joint threadcompound or Teflon tape may be provided on the threads to provide aweather-tight seal between the adapter 204 or gland 250 and the housing200.

An adapter body 204 may be configured to receive different types ofcable mating adapters 254 therein. The mating adapters may have aplug-in socket at each end thereof configured for any type ofmulti-fiber connectors to mate the terminal ends of the connectors. Asan example, adapters 254 may be configured to mate incoming connectorsof types MPO (or similar), with another connector of type MPO (orsimilar). In a variant embodiment, the adapter may be one-piece adapters304 as depicted in FIG. 10, and may include an integral internal cablemating configuration of any of the types as described above. For anintegral adapter 304, instead of inserting a mating connector 254 withinthe adapter 204, the user would only need to select and install anappropriately configured adapter.

As represented in FIG. 5D, an end 204 b may have an elongated threadedportion 204 c adjacent the flange 205. End 204 b may be inserted througha knock-out opening 29 of a panel wall 28 (as represented in FIG. 1) tothe position in which the flange 205 rests against the panel wall, sothat the threaded portion 204 c extends through the wall. A lock-nut 27may be inserted onto the end 204 b and threaded onto the threadedportion 204 c to fasten the adapter 204 (and attached housing 200) tothe panel. The protruding end 204 b may be configured as a bayonetcoupling for connection to a bayonet connector, such as bayonetconnector 145 in FIGS. 2A, 2B. Additional coupling configurations mayalso be provided on the end 204 a.

For cable glands, such as the depicted gland 250 in FIGS. 5B and 5C, theend 250 b may be partially threaded for receiving the pressure dome 252.A sealing sleeve 253 may be provided within the dome 252 for beingdisposed about a through cable so that upon threading the pressure domeonto the end 250 b, the sealing sleeve may be compressed about the cableto provide a weather-proof seal about the cable while also providing aretention force for holding the cable with the gland. Various sizes andstyles of cable glands may be threaded to the housing 200 dependent onthe cable being used. For example sealing sleeves 253 may have a roundopening for round cables, or a rectangular opening for flat cables.

In an embodiment, instead of a cylindrical housing, such as housing 200with ends 200 a and 200 b disposed essentially along a linear axis, orat 180° from one another, a housing 300, as shown in FIG. 10, may bebent, or angled to adapt the housing for a particular use. In theembodiment represented in FIG. 10, end 300 a is disposed at an angle ofabout 120° from the end 300 b. In various embodiments, the angulardisposition between the ends may be from 90° to about 180°. As examples,end 300 a may be disposed with respect to the end 300 b at angles ofabout 180°, about 175°, about 170°, about 165°, about 160°, about 155°,about 150°, about 145°, about 140°, about 135°, about 130°, about 125°,about 120°, about 115°, about 110°, about 95°, about 90°, less thanabout 90°, or any angle between any of the listed values.

While the housing 200 represented in FIG. 5 has a circularcross-section, in various other embodiments (not shown), a housing mayhave a cross-section that may be rectangular, triangular, hexagonal, orvarious other configurations.

A fan out assembly 140 having six duplex fiber optic cables 108, similarto the representation in FIG. 4A with twelve cables, may be assembled asfollows. An unstrapped furcation tube 280 having duplex furcation tubes282 is represented in FIG. 7A. In an embodiment, for example, thefurcation tubes 282 may have an inner diameter of about 900 μm. Thefurcation tubing 280 may be cut to an appropriate length, as needed, anda portion d1 of a cable jacket 284 may be removed to expose thereinforcement members 285. The reinforcement members 285 may be Kevlarstrands. A portion d2 of the reinforcement members 285 may be cut awayto expose the furcation tubes 282 as represented in FIG. 7B. In anembodiment, for example, the distance d1 may be about 20 mm and thedistance d2 may be about 15 mm, leaving about 5 mm of reinforcementstrands 285 exposed, and furcation tubes 282 extending about 15 mmbeyond the reinforcement strands. If desired, about 1 mm of thefurcation tubes may be trimmed to make the tubes even.

After preparing the furcation tubes as discussed above, the tubing 280may be installed in a drum 202. The stripped portion of the tubing 280may be inserted into and through an orifice 240 of the drum 202 from theside 202 a until the end of the cable jacket 284 is approximately evenwith the inside surface 202 b of the drum as represented in FIG. 7C. Sixcable sections 280 may be installed in this manner.

The tubing sections 280 may be fastened with the drum 202 by means of anadhesive. In one embodiment, as represented in FIGS. 7D and 7E, the drum202 may be mounted vertically with the tubing sections 280 extendingbelow, and the recessed cup of the drum facing upwardly. A liquidadhesive, or potting compound 290 may then be injected around thefurcation tubes 282 to a level approximately even with the top edge 292of the drum 202. The adhesive may then be allowed to cure to affix thecable sections 280 with the drum 202. For simplification of thedrawings, the extending cable sections 280 are omitted from FIG. 7E, andsimilarly, only one is shown in FIG. 8. For some embodiment, theadhesive/potting compound 290 may be injected with a syringe. Theadhesive may be a two part formula that is mixed upon injection, and maybe self-leveling to essentially provide an even surface around theextending tubings 282. A cure time of about 2 hours may be sufficientfor curing of some potting compounds, while the cure time of variousadhesive -type materials will vary.

In an alternative configuration, that may provide an assembly withoutthe need for adhesive/potting compound, a drum 202 may have orifices 240a that include projecting teeth 298 projecting internally into theorifice. The teeth may be configured to allow the tubing sections 280 tobe inserted into the orifices 240 a along the direction of the arrow299, but prevent, or at least inhibit movement back out of the orificesin the opposite direction by biting into the jacket of the tubing 280.The configuration, placement and number of teeth 298 may be varied asmay be required for different situations. A sealant may be applied atthe orifices 240 a and/or the tubing 280 being inserted to weatherproofthe connection.

As represented in FIG. 5, the O-ring 215 may be installed onto theadapter 204 (or alternatively, a cable gland 250, FIG. 5B). Theadditional O-ring 212 may be installed into the end 200 a of the housing200, to a position as shown essentially in FIG. 4C. For an embodimentwherein the adapter 204 may include an IP-MPO mating adapter 254therein, a fan-out connector, such as a terminated MPO connector 293, asrepresented in FIG. 8, may be plugged into the mating adapter 254. Theterminated MPO connector 293 may include a plurality of individualfibers 294 extending therefrom. In an embodiment, the fibers may be 250μm fibers, and for six duplex cables, there may be twelve fibersextending from the connector 293. The fibers 294 may be fed through thehousing 200 from the end 200 b of the housing. Alternatively, in oneembodiment, the interior passage 210 of the housing may be sized forpassage of a connector, such as connector 293, therethrough. Housing 200may then be fastened with the adapter 204, such as by threading thehousing onto the adapter, and the O-ring 215 may be compressed betweenthe adapter flange 205 and the flange 201 a of the housing 200.

Individual ones of the fibers 294 may be fed into the potted ends of thefurcation tubes 282 of the drum 202 until ends 294 extend from the tubes280. For simplification, only one of the tubings 280 is shown. Afterfeeding fibers 294 into the furcation tubes 282 (two each per tube 280),the drum 202 and attached tubings 280, may be moved towards the housing(allowing the fibers 294 to move further into the tubes 282) until thedrum mates with the housing, aligning the key 222 with the slot 220.After the drum 202 seats against the O-ring 212, screw holes 226 and 228may not be fully aligned. A further inward pressure of the drum 202 intothe housing 200 may be needed to compress the O-ring and align the screwholes 226 and 228. Screws 225 may then be inserted to retain the drum202 in the housing 200 with the O-ring 212 sealing therebetween.

Duplex fiber optic connectors 122 a may then be installed onto the endsof the tubing sections 280 and the ends 294 a of the fibers 294. Aresulting fan-out connector assembly may be provided, essentiallysimilar to assembly 140 of FIG. 2A, except having 6 duplex connectors122 a instead of twelve simplex connectors 122. A finished assembly 140may be fastened in an antenna structure as represented in FIG. 1A, byclamping the housing 200 to a portion of the framework of the antenna.Alternatively, an assembly 140 may be installed via a knock-out into ahousing, such as housing 10 in FIG. 1B, by inserting the end 134 a ofthe of the connector through the hole provided by removing a knock-out.A threaded ring nut may be threaded onto the end 134 a to hold theconnector 134 in place within the housing 10. Dust/protective caps 138may be installed to protect the connection until ready to use.

In an embodiment, the fan out assembly may be used in a method forconnecting remote radio units of a cellular antenna tower with a basetransceiver station via a multi-fiber optical cable. The multi-fiberoptical cable may include a terminal connector, and the method includesattaching the fiber optic fan-out connector assembly 140 in a tower 1adjacent the remote radio units. This distance may, for example be about3 meters, 3.5 meters, 4 meters, 4.5 meters, 5 meters. In someembodiments, the distance may be more or less depending on the structureof the antenna. The fan-out connector assembly for the antenna tower mayinclude a housing defining an interior cavity, a plurality of pigtailcable segments extending from the housing, with each of the plurality ofpigtail cable segments having a first end disposed within the housingand a free end disposed away from the first end, at least one opticalfiber extending through each pigtail cable segment and having a firstend within the interior cavity and a second end at the free end of thepigtail cable segment, and optical fiber connectors mounted to the freeends of each pigtail cable segment and terminating the second end of theat least one optical fiber of the pigtail cable segment. The housing mayalso include a mating connector for connecting first ends of the opticalfibers with the connector of the multi-fiber optical cable, and themating connector may include a plug-in socket for receiving theconnector of the multi-fiber optical cable therein. Once the assembly isfastened in place, the procedure for connecting may include connectingthe second optical fiber connectors of the pigtail cable segments to theremote radio units, and connecting the multi-fiber optical cable fromthe fan-out connector assembly to the base transceiver station, theconnecting comprising plugging the connector of the multi-fiber opticalcable into the plug-in socket of the mating connector.

This disclosure is not limited to the particular systems, devices andmethods described, as these may vary. The terminology used in thedescription is for the purpose of describing the particular versions orembodiments only, and is not intended to limit the scope.

In the above detailed description, reference is made to the accompanyingdrawings, which form a part hereof. In the drawings, similar symbolstypically identify similar components, unless context dictatesotherwise. The illustrative embodiments described in the detaileddescription, drawings, and claims are not meant to be limiting. Otherembodiments may be used, and other changes may be made, withoutdeparting from the spirit or scope of the subject matter presentedherein. It will be readily understood that the aspects of the presentdisclosure, as generally described herein, and illustrated in theFigures, can be arranged, substituted, combined, separated, and designedin a wide variety of different configurations, all of which areexplicitly contemplated herein.

The present disclosure is not to be limited in terms of the particularembodiments described in this application, which are intended asillustrations of various aspects. Many modifications and variations canbe made without departing from its spirit and scope, as will be apparentto those skilled in the art. Functionally equivalent methods andapparatuses within the scope of the disclosure, in addition to thoseenumerated herein, will be apparent to those skilled in the art from theforegoing descriptions. Such modifications and variations are intendedto fall within the scope of the appended claims. The present disclosureis to be limited only by the teitus of the appended claims, along withthe full scope of equivalents to which such claims are entitled. It isto be understood that this disclosure is not limited to particularmethods, reagents, compounds, compositions or biological systems, whichcan, of course, vary. It is also to be understood that the terminologyused herein is for the purpose of describing particular embodimentsonly, and is not intended to be limiting.

As used in this document, the singular forms “a,” “an,” and “the”include plural references unless the context clearly dictates otherwise.Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art. Nothing in this disclosure is to be construed as anadmission that the embodiments described in this disclosure are notentitled to antedate such disclosure by virtue of prior invention. Asused in this document, the term “comprising” means “including, but notlimited to.”

While various compositions, methods, and devices are described in termsof “comprising” various components or steps (interpreted as meaning“including, but not limited to”), the compositions, methods, and devicescan also “consist essentially of” or “consist of” the various componentsand steps, and such terminology should be interpreted as definingessentially closed-member groups.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity.

It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to embodiments containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should be interpreted to mean “at least one”or “one or more”); the same holds true for the use of definite articlesused to introduce claim recitations. In addition, even if a specificnumber of an introduced claim recitation is explicitly recited, thoseskilled in the art will recognize that such recitation should beinterpreted to mean at least the recited number (e.g., the barerecitation of “two recitations,” without other modifiers, means at leasttwo recitations, or two or more recitations). Furthermore, in thoseinstances where a convention analogous to “at least one of A, B, and C,etc.” is used, in general such a construction is intended in the senseone having skill in the art would understand the convention (e.g., “asystem having at least one of A, B, and C” would include but not belimited to systems that have A alone, B alone, C alone, A and Btogether, A and C together, B and C together, and/or A, B, and Ctogether, etc.). In those instances where a convention analogous to “atleast one of A, B, or C, etc.” is used, in general such a constructionis intended in the sense one having skill in the art would understandthe convention (e.g., “a system having at least one of A, B, or C” wouldinclude but not be limited to systems that have A alone, B alone, Calone, A and B together, A and C together, B and C together, and/or A,B, and C together, etc.). It will be further understood by those withinthe art that virtually any disjunctive word and/or phrase presenting twoor more alternative terms, whether in the description, claims, ordrawings, should be understood to contemplate the possibilities ofincluding one of the terms, either of the terms, or both terms. Forexample, the phrase “A or B” will be understood to include thepossibilities of “A” or “B” or “A and B.”

In addition, where features or aspects of the disclosure are describedin terms of Markush groups, those skilled in the art will recognize thatthe disclosure is also thereby described in terms of any individualmember or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and allpurposes, such as in terms of providing a written description, allranges disclosed herein also encompass any and all possible subrangesand combinations of subranges thereof. Any listed range can be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein canbe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” and the like include the number recited andrefer to ranges which can be subsequently broken down into subranges asdiscussed above. Finally, as will be understood by one skilled in theart, a range includes each individual member. Thus, for example, a grouphaving 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, agroup having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells,and so forth.

Various of the above-disclosed and other features and functions, oralternatives thereof, may be combined into many other different systemsor applications. Various presently unforeseen or unanticipatedalternatives, modifications, variations or improvements therein may besubsequently made by those skilled in the art, each of which is alsointended to be encompassed by the disclosed embodiments.

What is claimed is:
 1. A fan-out assembly for connecting fiber opticcables of a multi-fiber optical cable to a plurality of fiber opticterminals, the assembly comprising: a housing defining an interiorcavity therein and having a first body portion and a second body portionspaced from the first body portion; a plurality of pigtail cablesegments having a first end disposed within the housing and a free enddisposed away from the housing; at least one optical fiber extendingthrough each pigtail cable segment, each optical fiber comprising afirst end disposed within the interior cavity and a second end disposedat the free end of the pigtail cable segment; a first optical fiberconnector collectively terminating the first ends of a plurality of theoptical fibers; at least one second optical fiber connector mounted tothe free end of each pigtail cable segment and terminating the secondend of the at least one optical fiber of the pigtail cable segment, thesecond optical fiber connectors being configured to mate with the fiberoptic terminals; and the housing comprising an optical fiber adapterlocated at the second body portion of the housing, the optical fiberadapter having a first end open to the interior cavity for receiving thefirst optical fiber connector therein, and a second end exposedexternally of the interior cavity for receiving a connector of amulti-fiber optical cable to mate the optical fibers of the multi-fiberoptical cable with the first ends of the optical fibers of the pigtailcable segments; wherein when the first optical fiber connector isreceived in the first open end of the adapter, each pigtail cablesegment extends continuously from the first optical fiber connectoradjacent the second body portion of the housing, through the interiorcavity of the housing, and out the first body portion of the housing tothe respective free end.
 2. The assembly of claim 1, wherein the housingfurther comprises: a fan-out member releasably attachable to the firstbody portion and comprising a plurality of spaced apart openingsextending through the fan-out member, with at least one pigtail cablesegment disposed in each of the plurality of spaced apart openings; andthe optical fiber adapter is releasably attachable to the second bodyportion.
 3. The assembly of claim 2, wherein: the main body comprises atubular member having a first axial end and a second axial end, thefirst axial end comprising the first body portion and the second axialend comprising the second body portion; at least a portion of thefan-out member fits internally within the first axial end, and at leastone of the first axial end of the tubular member and the at least aportion of the fan-out member comprises a first releasable attachmentfor engaging with the other of the first axial end of the tubular memberand the at least a portion of the fan out member to releasably attachthe fan-out member with the main body; and at least a portion of thecable receptacle fits internally within the second axial end, and atleast one of the second axial end of the tubular member and the at leasta portion of the cable receptacle comprises a second releasableattachment for engaging with the other of the second end of the tubularmember and the at least a portion of the receptacle to releasably attachthe cable receptacle with the main body.
 4. The assembly of claim 3,wherein: the first axial end defines a first cylindrical opening; andthe fan-out member comprises a disc-shaped member for being disposedwithin the cylindrical opening, the disc-shaped member having a firstside for being disposed towards the interior cavity and a second sideopposite the first side, with the plurality of spaced apart openingsextending through the fan-out member from the first side to the secondside.
 5. The assembly of claim 4, wherein: the second axial end definesa second cylindrical opening; and the first end of the optical fiberadapter comprises a first cylindrical end for being disposed within thesecond cylindrical opening, and the second end of the optical fiberadapter comprises a second cylindrical end spaced axially away from thefirst cylindrical end; the optical fiber adapter comprises: an interiorpassage through the optical fiber adapter from the first cylindrical endto the second cylindrical end; and a fiber optic cable mating adapterdisposed within the interior passage, the cable mating adapter having afirst end disposed towards the internal cavity and comprising a firstplug-in socket for receiving the first optical fiber connector therein,and a second end disposed away from the interior cavity for receivingthe connector of a multi-fiber optical cable to align and mate theoptical fibers of a multi-fiber optical cable with the first ends of theoptical fibers of the pigtail cable segments.
 6. The assembly of claim5, wherein: the first axial end comprises a stop for limiting insertionof the disc-shaped member into the first axial end, the stop comprisinga radial shoulder; and the assembly comprises an elastomeric sealingmember for being disposed between the shoulder and the disc-shapedmember to seal the disc-shaped member with the main body.
 7. Theassembly of claim 5, wherein: the optical fiber adapter comprises aradially extending flange for seating against the second axial end ofthe main body; and the assembly further comprises an elastomeric sealingmember for being disposed between the flange and the second end to sealthe optical fiber adapter with the main body.
 8. The assembly of claim5, wherein: the first releasable attachment comprises screws disposedradially through the first axial end of the main body and correspondingthreaded holes in a radially external surface of the disc-shaped memberfor receiving the screws therein; and the second releasable attachmentcomprises internal threads disposed radially within the second axial endof the main body and corresponding external threads on the first end ofthe optical fiber adapter for a threaded engagement between the opticalfiber adapter and the second axial end of the main body.
 9. The assemblyof claim 1, wherein a portion of each pigtail cable segment extendingaway from the first body portion of the housing to the respective freeend is freely movable with respect to the other pigtail cable segments.